The present invention relates to a printing press with a plate making unit which performs plate making for a plate mounted on a plate cylinder in a printing unit.
Generally, when performing plate making for a plate, it is required to increase the efficiency of plate making operation and to eliminate the space where a plate making unit is to be installed. Hence, in recent years, a plate making unit independent of the printing press is not provided, but a plate making unit added to the printing press itself performs plate making directly on the printing press. More specifically, a plate before plate making is mounted on a plate cylinder in a printing unit, and the plate making unit is moved to abut its head against the plate cylinder. Subsequently, the plate cylinder is rotated, and simultaneously the head is moved in the axial direction of the plate cylinder, thereby performing plate making for the plate. When the plate is to be supplied/removed or maintenance is to be performed, the plate making unit is separated from the printing unit.
In a printing press of this type, the front surface of the printing unit which opposes the plate cylinder has an opening so that a plate can be supplied to or removed from the plate cylinder and the maintenance for the inking unit and the like can be performed. An openable safety cover is provided to this opening to close it during printing. In the conventional printing press described above, a movable plate printing unit must be provided, together with an openable safety cover, between adjacent printing units. For this reason, the work space for the operator in front of the printing unit is narrowed, and the workability is decreased. Since both the safety cover and plate making unit are movable, and must be arranged in a limited space in front of the printing unit, the entire structure becomes complicated.
It is an object of the present invention to provide a printing press in which the workability of an operator during plate changing operation, maintenance, and the like is increased.
It is another object of the present invention to provide a printing press with a simplified structure.
In order to achieve the above objects, according to the present invention, there is provided a printing press comprising a printing unit with a plate cylinder, a plate making unit provided in the printing unit and adapted to perform plate making for a plate mounted on an outer surface of the plate cylinder, the plate making unit being supported to be movable between an operative position where the plate making unit performs plate making while closing at least part of the printing unit, and a wait position where the plate making unit opens at least part of the printing unit, and control means for selectively operating the printing press at a first speed at which normal printing is performed and a second speed lower than the first speed, the control means serving to enable the printing press to operate at the first speed when the plate making unit is located at the operative position, and disable the printing press to operate at the first speed when the plate making unit is not located at the operative position.